The present invention relates generally to a liquid filter. More particularly, this invention relates to filtration apparatus for removing particulate contaminants from commercial laundry waste water and a method for accomplishing the same.
Many state and local governments across the country have enacted environmental regulations or expanded existing regulations to limit the amount of particulate contaminants discharged into the environment. The regulations are generally directed toward commercial enterprises which create various wastes as a by-product of manufacture or of doing business. The commercial laundry industry and commercial laundromats, in particular, are affected by regulation limiting the amount of suspended solids or particulate contaminants contained in waste water that is discharged into the ground water and/or municipal sewage system. Particulate contaminants in commercial laundry waste water generally consists of lint, hair, dirt and soap scrim. To meet these stricter environmental regulatory requirements a certain amount of the particulate contaminants in the waste water must be removed.
Removal of particulate contaminants is generally accomplished by filtering the liquid. A number of filter devices have been invented to remove particulate contaminants from liquids. For example, U.S. Pat. No. 4,322,293 by Morgan discloses a filtering device having a housing which supports and suspends a number of multiple filter elements which have a single open upper end which accepts the liquid to be filtered. Once the filter is clogged or full the housing must be opened and the filters removed and replaced or cleaned.
Another example, U.S. Pat. No. 4,591,446 by Muller discloses a pressurized filtering device in which the liquid to be filtered transfers through a plurality of vertically suspended tube-like filter elements wherein particulate contaminants accumulate on the outer surface to the filter elements. A second operation of rinsing the outer surface of the tube-like filter elements with a combination of a rinsing liquid and pressurized air removes the particulate contaminants accumulated on the outer surface of the filter element for subsequent discharge of the contaminants out a separate opening at the bottom of the device.
In both of the above disclosures once filtration of the liquid is undertaken the effective filtering capability of the filter device decreases due to clogging of the filter. To satisfy the needs of the laundry industry a filtering apparatus should be capable of accepting a large flow rate of waste water and capable of removing the relatively small suspended particulate contaminants.